A milestone in the development of improved tire inner liners was announced today by ExxonMobil Chemical Company and The Yokohama Rubber Co., Ltd. (YRC) following tests to qualify their jointly developed technology for use in passenger vehicle tires in harsh winter conditions.
The companies’ development of DVA (dynamically vulcanized alloy) advanced tire inner liner technology is based on proprietary Exxpro™ polymers and alloys of those polymers developed by ExxonMobil, as well as alloys and application technology developed by YRC. The DVA advanced inner liner technology used in the film liner materials combines the flexibility and elasticity of a rubber with the low-air permeability of a plastic.
Satisfying low-temperature fatigue-resistance requirements is difficult for conventional inner liners. Tires made with the jointly developed DVA advanced inner liners passed rigorous cold-temperature indoor tire testing and outdoor road testing. Tests were conducted over a six-month period in northern Canada in temperatures reaching -220C.
In addition to their cold-temperature toughness, 15-inch V-rated passenger car tires using the DVA advanced inner liner have shown light-weighting gains of approximately 5.5 percent or 0.5 kg per tire, and reductions in rolling resistance. These results are due to the exceptional air-retention properties of the DVA, which can be 7-10 times better than those obtained from conventional 100 phr halogenated butyl rubber (halobutyl rubber) liner compounds. Tires with lower rolling resistance have been shown to improve vehicle fuel efficiency.
In 2004, ExxonMobil Chemical and YRC announced a joint cooperative agreement and ExxonMobil’s acquisition of a global license from YRC for DVA inner liner technology.
In October 2005, ExxonMobil Chemical announced a multimillion-dollar investment to double production capabilities for its proprietary Exxpro™ specialty elastomer used in DVA advanced inner liner construction. The expansion of the company’s plant in Baytown, Texas, is targeted for completion in the fourth quarter of 2006.
ExxonMobil Chemical expects to commercialize a DVA resin product in the latter half of 2007. ExxonMobil Chemical is a major supplier of halobutyl rubber to the global tire industry.